The Girlfriend (2013)
by SEZCPL
Summary: (Back by popular demand). Derek's new friend is just like him: girl-centric, so when he has a new target in his sights Derek is intrigued...until he realises it's Casey and is forced to act. Let the fun begin! [This has been edited slightly rather than re-written and to save time is republished in one block. Sorry it's taken so long!]


Title: **The Girlfriend**  
Category: TV Shows » Life With Derek  
Author: SEZCPL  
Language: English, Rating: Rated: M  
Genre: Humor/Romance  
Published: 07-25-09, Updated: 09-06-09  
Chapters: 21, Words: 14,650

**Chapter 1: The Player**

"Now _that_ is HOT!" Jez exclaimed, burger half-way to his mouth. Derek smirked at his new roommate.

"You know. I never thought I'd meet someone who was as chick-focused as me, but maybe I was wrong."

"Yeah but…Jeez D. She is something else. No NO! Don't turn round. I'll describe her." Derek's smirk got bigger.

"Slim with just enough butt to grab, not too tall, not too short, hair dark soft and wavy, deep blue eyes. Smile that can light up a room. Tits like ripe peaches, just waiting for…"

"I get the picture." His roommate laughed. "She sounds perfect."

"Ah. But I saw her first. New roommate rule, no poaching each other's candy."

Derek bit into his own burger. Jez was a nice guy. He'd done well with his dorm allocation. His new roommate kept his mess to a minimum, had similar music taste, and sounded like a guy who would not get upset over needing to vacate the room for "visitors". Derek was sure over the course of the year, there would be visitors.

"I can see her climbing my bedroom walls with me now. She looks like she would know what she was doing. I might need you to disappear for a while tonight."

Derek chuckled. "You're that sure of your skill?"

"Aren't you?"

_Nice guy. But, I would not let him near a grown up Marti though._

Jez started giving him a running commentary on the girl and her party.

"Good looking friends too. Nice. Maybe possibilities when it's all over with cute cheeks. Cool T. Muse import. Not easy to come by."

"I know. It took me forever to get Casey's for her birthd…" Derek went cold.

_Dark hair, blue eyes, medium height, cute butt – did I just call Casey's butt cute?_

He spun round and his eye met the perfect blue ones of Casey McDonald. His step-sister. Oh fuck!

He turned slowly back round to face Jez who was looking at him in surprise.

"Jez Dude. You cannot date her."

"Why?"

"She's my…" He should say sister. He should say step-sister. What he should not do is LIE and say…

"Girlfriend."

"Girlfriend?! I thought you were single."

_Bollox_.

"Yeah well, you know how it is. High school romance. Haven't told the rents…"

"If you're getting bored with her let me take her off your hands."  
"I'm not getting bored with her. It's just awkward."

_Awkward! Not as freaking awkward as it will be if Casey ever finds out you just claimed to be her boyfriend! She hates you. Hang on… we hate each other._

"So why didn't you tell her you were coming out for dinner tonight? She and her friends could have joined us. Actually they still can. Go on, introduce us."

Derek could feel a sense of panic rising.

"No Jez man. She and I agreed to not be in each other's faces all the time."

"Hey. If she was my girlfriend, I'd be in her face ALL the time. In all the dirty ways you could possibly imagine."

Derek had a sudden flash of Casey and him doing something "dirty" and also…_god did I really just think that?_...incredibly hot.

_Nuns! Think of nuns, Derek._

"Well if you aren't going to say hello. I certainly am!" Jez started to stand up.

Derek stood up abruptly.

"No! It's ok. I got it."

He eased his way out of the booth and over to his step-sister's table. She was standing beside it, removing her cardigan before sitting down.

Derek could feel Jez's eyes boring into his back. He took a deep breath. Casey looked up.

"Derek?" She asked in astonishment. He had a really weird expression on his face.

"Hi Babe!" He said, loudly enough for Jez to hear. Then he put an arm around her waist, bent his head to hers and slipped his tongue between her lips.

**Chapter 2: The Hygienist**

Casey's mind was whirling and her heart was racing. She was also low on oxygen. If you know you are going into a deep kiss, you stock up on air first. Derek really hadn't given her that choice.

He still wasn't giving her much of a choice.

His arms were tightly round her, their lips were moving together, and Casey was seriously considering cancelling her next dental hygiene appointment, because she doubted her hygienist would be that thorough. His leg was also between hers, pushing up against her and she was trying not to think about the rock hard object pressing against her thigh.

If she didn't do something soon, black spots would appear in front of her eyes. The last thing she was ever going to do was pass out because Derek kissed her. She would _never_ live that down.

Then he pulled away.

He moved his lips to her ear and whispered.

"The prince is yours for the next month if you don't hit me until we're on our own."

She rallied. "Three months."

"Two. And you follow my lead…okay?"

"You _so_ owe me, Derek Venturi." She threatened.

"Consider the kiss part-payment." He smirked against her lips.

"D-Man! Are you going to introduce us?" Jez appeared at his elbow.

Derek kept an arm around Casey and turned them towards his roommate.

"Jez. This is Casey McDonald, my girlfriend. Casey, honey, this is Jez, my roommate."

"_Girlfriend!_" Casey muttered under her breath.

"_Ok. _Three_ months_." Derek muttered back and pecked her on the cheek.

"Hi, Casey! Nice to meet you at last. Derek's told me a lot about you."

"Have I?" Derek asked in a strangled voice. Casey raised an eyebrow.

"_No. But you will when we get back to the dorm._" Jez whispered.

"Oh that's Der-bear for you. Can't stop talking about little ol' me." Casey pulled a face. She was going for a "winning smile" but to Derek it looked just like a grimace.

One of Casey's friends stood up, an amused look on her face.

"Since we've heard nothing about either of you two _gentlemen_, would you care to join us?"

Casey looked at her in horror.

"Actually, I've just remembered I need to collect something from Derek's dorm, so we can't stop. I'll see you guys back at the common room." She blustered and pushed Derek towards the door.

"I'll…um…see you later Jez." He forced the words out.

Jez chuckled and mouthed the words "tie" and "doorknob" at him. Derek groaned as Casey pushed open the door and yanked him outside.

**Chapter 3: Casey Reacts**

He supposed he should be grateful she waited.

Waited exactly one block and one alley before….

SMACK!

Casey's palm collided with Derek's face. He winced and backed away towards the wall.

"Who the hell do you think you are that you can waltz up to me" she jabbed him in the chest. He took a step back.

"and _kiss_ me…" Jab. More steps backwards.

"…like you own me? That was so _freaking_ embarrassing in front of my roommate and friends."

She shoved him.

"Never mind the fact that cute boy from Creative Writing was at the next booth. And your tongue….ewww…"

"What's wrong with my tongue?" He managed to ask.

"It's so _long_!" She spluttered. "And so…alive."

He chuckled. Bad Move.

Casey started with the jabbing again.

"You" jab

"Are" jab

"an" jab

"ob-" jab

He caught her hand.

"Yeah. "obnoxious jerk", I get the picture. Now can you stop with the jabbing please."

Casey smiled.

"Of course Derek, darling."

She lifted her knee and scored a direct hit between his legs. He crumpled to the ground. Casey turned on her heels and started back down the alley.

"Does that mean you're dumping me?" He gasped after her.

Derek was lying on his bed. It was about all he was capable of doing at the moment. Dating…would be a sore subject for a few days. He turned over and winced.

Make that a few _weeks._

Not that he could really blame Casey. How the hell had he got himself into the situation anyway? Still, at least Jez would stop going on about dating her.

Bang! Speak of the devil.

"Yo. D Man. What's with the no tie on the door knob? I thought I was going to have to crash in the common room tonight. Casey looked like she was ready to eat you. Or did she and you've kicked her out already?"

"We had an argument. She cleared off home."

"You broke up? Cool! Does she like red roses or white?"

Derek sighed exasperated. "No. We didn't break up. She just got pee'd off at me over something I said. She'll be fine when I speak to her. Stay away from her."

"OK. I'll take a look at her friends instead."

"No. I don't need grief because you boned one of her friends and left her high and dry. Casey and her friends are off limits, Okay."

Jez looked disgruntled. "Okay. But the moment you split up…I'm in there D."

Derek groaned and pulled his pillow over his head.

**Chapter 4: Same Difference**

"So Derek Venturi…"

Casey groaned. She had been hoping she could make her sandwich quickly and get out of the shared kitchen before the others returned home. Then she had planned on pretending on being asleep until they were snoring.

Instead, Caroline was leaning against the kitchen sink looking at her with amusement.

"Yes. It was." Casey said without enthusiasm.

"Lucky old you."

"Hardly."

"I didn't know you knew the up and coming young hockey god."

_Please not here as well. Surely the campus is big enough I don't have to listen to the girls lusting after him all day long here the way I did at school!_

"We went to school together."

_And thanks to Derek's little prank, I can hardly tell them he's my step-brother. Then I would get labelled as weird for kissing my sibling. Even though I didn't kiss him and strictly speaking there is nothing _wrong_ about step-sibling relationships. God, Derek and me….ew!_

"That was one hell of a kiss. I bet he's great in bed. How long have you been dating?"

Casey paused. What she should have said was…

_Not long and to be honest I'm thinking of splitting up with him. Oh and he's pathetic in bed._

What she actually said was…

"About six months. I don't talk about my sex life."

_What the hell, Case!_

"Cool. Well. When you get bored, put in a good word for me."

Casey gave a small smile…and hear all about Derek's prowess in bed. Not freaking likely.

She finished her sandwich and made her way back to her room. She perched in the bed, sandwich in front of her, thinking about the incident in the diner. She was trying to analyse Derek's reasons for kissing her, but all she could concentrate on was the way he looked at her before he kissed her, and the feel of his lips on hers before his tongue entered her mouth. She was still trying not to think about the tongue.

Anger got the better of her. She leant over to her bedside cabinet and picked up her cell phone.

**Keys 2 the Prince tomorrow AM b4 10 or I tell every1 U frenched Ur sister.**

She pressed transmit.

Thirty seconds later, her phone buzzed.

**Behind the lib build 9.30. STEP-sister**

Casey chuckled.

**Same Diff.**

**Chapter 5: Truman**

Derek didn't sleep well and it was only partly down to the pain in his groin. The main reason was the pain in his neck…Casey. He wasn't entirely sure why he had done what he did in the diner. Casey was a big girl, she could look after herself, and she wasn't really his sister so it was not necessary for him to be protective.

Besides, Casey would probably hate Jez. He was too like Derek.

Actually, Derek admitted to himself, Jez was a jerk. Derek wouldn't even _think_ some of the things Jez vocalised.

The trouble was, Derek _had_ kissed Casey in the diner and now he had to get out of the mess he was in.

The common sense approach would be to back away and let the heat die down. To just tell Jez that he had broken up with Casey, and let nature take its course. (If Casey was stupid enough to date the guy, who was Derek to stop her?) There was one word which stopped him from adopting this approach.

Truman.

Derek had been around for that fiasco – the first time, the second time…And so on until the final time when, faced with the fact he might actually be required to make a bit of an effort for his girlfriend, Truman had finally, properly dumped her.

Derek had actually shaken Truman's hand on that one. For once, the jerk had been honest with Casey and for that Derek gave him kudos. Truman had also warned Derek it was on the cards and made sure he was nearby to take Casey home.

Her step-brother had been forced to revise his opinion of Truman at that point. (But only slightly. He'd since heard from Sam that Truman had been seen with Vicky again.)

But just because he had a slightly elevated opinion of Truman these days, did not mean he wanted to go through all that again. Jez and Casey was a really bad idea.

Casey and Derek, however, even in a "pretend" form, was also not ideal. But, he had to admit, having seen some of Jez's moves over the past couple of weeks, it was probably better than Casey and Jez. Now he just had to persuade Casey to agree to his little deception.

Ha ha ha ha ha ha ha ha ha!

He ran his fingers through his hair. That was going to be tricky.

**Chapter 6: The Pact part one**

"Very amusing, Derek."

"Whajfnoeofjlsdnck."

"I can't hear you…."

Derek removed his hockey helmet. "I said, 'what's very amusing?'"

Casey motioned towards him. "That."

He was dressed in full hockey kit, helmet, padding, protective box…

"Early hockey practice."

"Don't you normally change at the rink?"

"Running late. Thought I'd change in my room."

She laughed. "And this wouldn't have anything at all to do with my damaging parts of your anatomy yesterday…"

He shook his head. "Didn't feel a thing."

"Really?" She took a step towards him. He jumped back out of her way, hands in front of his groin.

"Derek, you're walking like John Wayne."

"I can talk like him too."

"I haven't got time for this. Where are the car keys?"

He produced them from his bag and waved them out of her reach.

"Uh – uh. There's a condition."

"I hardly think you are in a position to bargain."

"Listen sweet cheeks, I've already agreed to let you have the car for two months…"

"THREE".

"Okay, three months. I just need you to do me a little favour."

"I did you a big favour yesterday. A massive favour. A "once in a life-time"…"I am SO never repeating it" favour."

"Which was then negated by the fact that you decided to impair my ability to have mini-Dereks in later life."

"Negated! Der-ek! You stuck your tongue down my throat. You think I'm not scarred for life?!"

"Hey babe. Women pay and queue round the block for what you experienced free of charge, yesterday."

"I always said you were a wh….I'm not going to say that word. And…Mini-Dereks? People like you should be sterilised at birth. I can't believe any sane person would ever consider carrying your child."

"I'll remember that one, hun."

Their eyes met.

Eventually, Casey's eyes narrowed. "Meaning?"

"Meaning…When I'm being doted on by my posse of grandchildren and you're just a barren old maid."

"I'm NOT going to end up an old maid."

"You are if you object to a hot guy sticking his tongue in your mouth."

"That depends on your definition of "hot"."

"Come on, Casey. Admit it. It wasn't such a bad experience as all that…was it?"

"Well no. There was one bit I liked."

Derek took a step towards her.

"Oh?" He murmured.

"Yes. The bit where you fell to the ground in agony after I kneed you. Now can I have the car keys?"

"No. We still haven't discussed my condition."

"Okay…I'm listening."

"That kiss thing…"

"Yup…"

"I need you to do it again. Possibly more than once."

**Chapter 7: The Pact part two**

_I need to watch her knees….looking at her chest was what got me in trouble last time. Too busy looking at her breasts- missed the rising knee. Not making that mistake again._

_She's quiet. Why?_

_Oh. Now she's laughing._

_Okay. That laugh is SERIOUSLY scary._

"Casey. Calm down. Case…Casey!"

Casey was having a major freak out. She sounded like a hyena on nitrous oxide and he was rather worried about her colour.

So Derek did what he had to do.

No. He didn't smack her. Derek doesn't hit girls.

He kissed her.

It was dangerous. It was foolhardy. But hey…he was wearing padding. And he needed to bring her out of this….fit. So he stepped forward, pulled her into his arms and kissed her.

This time he left out the tongue. He decided it was safer. His lips touched lightly against hers and she parted her mouth. He would have thought it was her joining in, but knowing Casey she probably just needed air. His mouth moved against hers for a moment. He pulled his lips away but kept hold of her.

Casey was speechless; breathless and speechless. She still looked a little weird.

"Sorry. But it was either that or slap you, and I couldn't face the conversation with your mother if I hit you."

"Like the "I kissed your daughter" conversation would be any easier." Casey murmured. She looked up at him.

"That wasn't quite so gross."

"You mean I kept my tongue under control?" He said softly. "Casey, I know this whole, kissing your step-brother thing is not cool, but I really need this favour. I need you to carrying on pretending to be my girlfriend for two weeks."

"Why?"

Derek had the lie lined up.

"Because Jez came onto me the other day and I need him to get the message that I'm straight."

"What?!"

He was rather pleased with the lie. It was a double whammy. First, it gave him a reason to need a girlfriend in a hurry and second, because, Casey would now think Jez was gay….and therefore, not boyfriend material.

"Oh." She said. "Not good."

"Nope."

"That's weird. I was convinced he was checking me out in the diner."

"Ego, much."

"Be nice."

"I am Case. Or hadn't you noticed." She was still in his arms. Shouldn't she have forced her way out of them by now?

"_Pretend_ girlfriend?" She asked.

"Uh Doh. Anything else is too grim to contemplate, Spacey."

"Good. We're on the same page about that at least. How many kisses are we talking about?"

"We're going to keep score?"

"Oh yeah. I say no more than one a day." He pulled a face "Two a day – morning and evening. No more than fourteen kisses. That's my final offer – oh and no tongues."

"Casey. Casey. Casey. Do you want me to _look_ like I'm dating my sister, coz if you put restrictions on my performance…."

"Ok…ok. Unlimited kisses. Just keep the tongue action to the minimum."

"Oh and I might need you to crash at mine a couple of times a week."

"What! What about my reputation when people find out I'm 'sleeping' with you?"

"It'll be so stoked! I should put that on the Casey Rewards list."

"DER-EK!"

"So do we have a deal?"

"Till a week on Sunday?"

"Yup."

"And the cars mine for three months?"

"Yup." He looked quite cheery.

"Okay then. It's a deal."

"Way-to-go, Casey." He kissed her on the forehead.

"You can let go of me now."

**Chapter 8: The First Lunch Date**

Casey slid into the seat next to her roommate, Caroline, in the lecture hall. Her other friends, Leesa and Petra were on the next seats over.

"Where did you get to at breakfast?" Caroline asked.

"Sorry. I had to meet someone."

Petra frowned. "At that time of the morning?"

Caroline grinned. "I don't blame her. If I was dating Derek Venturi I think I'd be sneaking off for secret assignations at weird times too. Mind you, I probably wouldn't have been home the night before!"

"Casey is dating _Derek Venturi_?!" Leesa screamed it across the auditorium. Several (interested) heads turned round to stare.

Casey slunk down in her seat, nodding…and blushing.

"That is SO cool! Just when I was worried my social life was never going to take off….Oh Casey! I am buying you the biggest Christmas present ever!"

_Oh God! It's Emily all over again!_

"You haven't heard the best bit." Caroline leant across Casey's desk to the girls the other side. "She didn't meet him here. She went to _school_ with him."

_Yeah. And I LIVE with him at home….I wonder what they'd say if they knew he was my brother – step-brother. I am not dating – correction…pretend-dating - my brother!_

"Ladies and Gentlemen! Let's do some work people!" The lecturer cut across her thoughts.

"So come on then, Case. I want to hear all about Derek." Leesa had tucked Casey's arm under her own and was walking her through the cafeteria for lunch, a tray balanced in her free hand. As she passed each table she heard "Hi Casey!" "Nice to see you Casey!" The Derek effect was obviously working.

"What do you want to know?"  
"What's the sex like?" Caroline interjected, plonking her butt down on a seat at a vacant table and removing her sandwich from her bag.

"I'm not answering that."

"Spoilsport."

"So when do we get to meet him?" Petra asked, semi-casually.

"Right now by the looks of things." Caroline pointed across the room. Derek was making his way through the crowds, carrying his own tray. Casey felt herself blush as she realised more than half of the students in the room were staring at her in anticipation.

He slid his tray onto the girls' table, sat down on one of the spare chairs and pulled Casey dramatically into his lap.

"Hey Spacey! Miss me?"

It took every ounce of restraint in her body not to slap him round the face. He noticed her uneasiness and bent his lips to her ear as though he was going to kiss her neck.

"We have an audience, Casey. For gods sake, just kiss me. And try and look like you mean it." Then he nuzzled her neck in a way that sent a shiver down her spine which she told herself was a shiver of horror.

Casey stopped him from exploring her collar bone by grabbing his head in both her hands and lifting his face to hers. She leaned in and kissed him on the mouth.

Derek's arms tightened around her, his mouth opened slightly and he responded.

The first two times Derek had kissed Casey, she had remained passive, not moving, waiting for the experience to be over. Right now…Casey was kissing Derek and he found to his surprise she was very good at it. Very very good. So good it would be easy to get lost in kissing Casey. He let his hand play with her t-shirt as they kissed, enjoying the feel of her hands in his hair. He was rather glad he was wearing jeans as they hide misdemeanours well and he was fairly sure Casey would freak if she knew the effect she was having on certain parts of his anatomy.

Maybe the next two weeks was going to more interesting than he had previously thought.

Casey pulled away. Their wild eyes locked on each other.

"Wow. That was hot!" Casey heard Leesa gasp quietly. Derek broke the staring match and turned to the rest of the girls.

"Hi Ladies."

"Hi Derek!" They chorused. Casey groaned. _Just like school._

Lunch passed, for Casey at least, in a bit of a blur. This was such a strange situation. She was sitting on Derek's lap with his arms around her, eating with her friends, painfully aware that much of the cafeteria were watching the scene play out in front of them. Derek didn't kiss her again, but one of his hands was toying with the bottom of her t-shirt, lifting it slightly and brushing the skin underneath.

She reached down and pulled the hand up and out of trouble. Public kisses was one thing. Private stroking was something completely different. Derek frowned at her action and Casey realised he was probably acting on auto-pilot; girlfriend on lap – time to cop a feel. Actually, it was so Derek-like it was quite amusing. She felt the corners of her mouth turning up into a smile.

_Why did Casey just move my hand? Oh. I suppose it was straying. I guess I forgot what I was doing. It is incredibly easy to forget that it is Casey on my lap. Something's making her smile. She looks prettier when she smiles. What is that scent? She must have changed her perfume. It's less of a girly scent that she used to use. I like this one. Probably a good job. If we make a habit of her sitting like this, I'm going to reek of it before long. That Leesa girl is irritating. She is SO like Emily, though Emily was at least reasonably good looking. Petra's not much better. Caroline has obviously been around the block at least once. She likes to make out she's widely experienced but I doubt it. I suppose I might have gone for her at one time. I guess dating is out of the picture till this Jez business finishes. Great. Another dry spell. It could be worse of course. I have at least got a girl. Even if it is Casey. And at least she's easy on the eye. I wonder if it's time to kiss her again. That last kiss was a surprise. I guess she's not as inexperienced as I didn't give her credit for. I wonder how far she actually has gone. I mean there have been a few guys...definitely not Sam. He only reached that goal last year, he told me. Max? Nah. He goes back to Amy when he wants that. Truman? God I hope not! Oh. Jez just came in. Good he hasn't spotted me yet. Time for a little more Casey action._

Casey jumped as Derek began kissing her neck. She could feel the colour rising in her cheeks. Then she spotted Jez walking towards her. _That explains that then._ She picked up Derek's hands, laced them openly in her own and turned her head towards his lips. He grinned at her as their lips met.

It took Jez three goes to get Derek's attention. His roommate broke off from the kiss, slightly short of breath.

"Oh for heavens sake, you two, get a room…"

Derek smirked. "What's up?"

"Coach wants to see you. Something about tonight's game."

"Ok." Derek started to shift Casey from his lap. She let him lower her to the ground.

"I gotta go, Princess. You'll be at the game." He made it into a statement.

"I was…" Casey started to protest and then saw the pointed look in her step-brother's eyes. She nodded, reluctantly.

"Good girl." He bent to kiss her on the lips. "See you later."

"What?" She said when Derek had gone and she looked up to see her three friends staring at her. Caroline smiled.

"Nothing. We're just all wishing we could swap places with you right now."

Casey allowed herself a small smile.

**Chapter 9: The Hockey Match part one**

"Leesa. Why are you dressed like Mr Frostie?"

"I'm coming with you to Derek's game."

"How much do you know about ice hockey?"

Leesa shrugged.

Casey continued. "It's not _that_ cold hun. An extra jumper would have done it. And why are you bothering anyway?"

"Derek has friends."

Casey groaned. "Leesa. Believe me. You do not want to be a hockey widow."

"Oh yes I do. And I am relying on you to provide me with possible hockey husbands."

Casey shook her head in resignation and gave in.

She knew how it went. She'd been his sister for too long. Hockey girlfriends had to follow a set of rules. You turn up forty five minutes before the game, you sit in the girlfriend pen, and you always wear the hockey jersey.

Well that one was down to Derek, because she didn't have his.

"Hi Princess!" He called. He was standing near the entrance as if waiting for something. He threw a bundle at her and she caught it.

Derek's practice jersey. Casey rolled her eyes. He grinned and walked up to her.

"Wear it. Please."

"Oh God. I'm a hockey widow."

Derek planted a kiss on her nose.

"Best yet." He grinned and walked away. She watched him strolling down the corridor nonchalantly and then he stopped, grabbed his stomach and ran for the men's room. Casey chuckled.

_You are so predictable, Venturi._

**Chapter 10: The Hockey Match part two**

"Leesa. If you hang over the glass like that, you'll get us thrown out of the arena."

"But that's Todd Matthews down there. Oh my God he's staring at me! I am SO in there. Hi Todd!"

"Leesa. He's staring at you because you are disrupting the game. SIT DOWN!"

Derek looked up from the ice at Casey, in amusement. He glanced around the girlfriend pen.

Impressive. Unintentionally, he seemed to have the hottest girlfriend there cheering for him. He considered taking Casey for pizza afterwards as a thank you. Even step-sisters need treats.

Then he spotted Leesa…after he'd got rid of the friend.

"That was awesome!" Leesa enthused. "All that male, hunkability. I'm drowning in testosterone."

"Drowning in caffeine, more like." Casey smiled as they made their way down to the dressing room corridor – another girlfriend routine. As a girlfriend she needed to be enthusiastic. It wasn't difficult today, Derek had played exceptionally well and she was genuinely rather proud of him.

Several of the other players' girlfriends were waiting too. A couple came over to congratulate Casey and she quite liked the reflected glory. Leesa was getting annoying, both to Casey and the other girls and the former was really regretting bringing her friend.

A freshly showered Derek emerged from the changing rooms already looking for Casey. He looked pleased when he saw she was waiting directly opposite the changing room door. He was impressed she remembered the girlfriend etiquette. She was leaning up against the wall in her fitted coat and skinny jeans. Her hair was slightly curly on her shoulders and there was an amused smile on her face. He noticed several of his teammates checking her out as they walked past. Nice one Casey! Definitely, pizza!

Casey had noticed the approving eyes too. She decided her familial pride in her step-brother necessitated a little exuberance in the congratulating girlfriend stakes – and Derek would appreciate the ego rub in front of his teammates…

"Hi Princess!"

She leapt up into his arms, legs around his waist and kissed him soundly on the lips. Derek dropped his kit bag and caught her, opening his mouth in response and gasping in surprise as her tongue joined his.

"Go Champ!" She giggled as she pulled away.

He backed her into the wall and kissed her again.

"What did I do to deserve that?"

"I thought your teammates might appreciate it."

He laughed. "Never mind them…I appreciated it. Pizza?"

"I've got Leesa with me." Casey pointed down the corridor to where her friend was waiting.

"I know." He smirked and motioned to one of the younger players on the team.

"Matt. Here's some cash, see Leesa over there? Take her out to the movies. If she has a good time, I'll have a word with the coach about you starting next week."

Matt nodded and disappeared off to see Leesa.

Casey frowned at Derek. "Not ethical, Derek."

"Your point is?"

"DER-EK!"

He laughed. "Pizza?"

Casey sighed. "Are you paying?"

"Of course. You already paid your way with that little greeting just now."

"Cool. You're on."

The pizza restaurant was near to the ice rink, so it was full of hockey players and their girlfriends; which necessitated more cover-protecting kisses. Casey sighed. She really should have stuck with the limited number of kisses arrangement. She'd lost count of the kisses already.

Actually when Derek kissed her, Casey lost a lot of things, including her mind. Pretending to be Derek's girlfriend was very….distracting.

**Chapter 11: Smarti and Nora**

"Hey Smarti! How's my little purple princess?" Derek was lazing on his bed. He hadn't rung home in a while and rather irate little sister had persuaded her father to let her phone Derek's cell phone.

"Don't you love me anymore, Smerek?"

"Of course I do, Smarts. I'm sorry. How's Daphne?"

"Daphne was a childish figment of my imagination which I no long require."

"Oh. How's Dimy?"

"Dimy is a smelly _boy_ and no longer one of my friends."

"Ok. And Lizzie?"

"Is _so cool_! Oh I'm so glad dad married Nora!"

"R-ight." _So that's how the land lies!_

"How's Smasey?"

Derek wasn't sure why the question made him go cold.

No. He knew _exactly_ why.

Because Smarti asking after Casey made him remember that Casey was Marti's step-sister and Marti was Derek's blood sister which meant that Casey was Derek's step-sister too.

And he had spent most of the last three days kissing her.

"Casey's fine, Smarti. You can tell Nora to stop worrying."

Nora took the phone from her step-daughter. "Is she eating okay, Derek?"

"As far as I can tell. She doesn't look like she's losing weight."

_There is absolutely nothing wrong with Casey's figure._

"When did you last speak to her?"

"About ten minutes ago."

_When I kissed her goodbye, very publicly, outside my dorm._ (Jez had been talking to a group of people outside.)

"Oh." Nora hadn't been expecting quite such a satisfactory answer. "You aren't pranking her too much, are you?"

"Not at all, Nora. Chill."

"Okay. Here's Marti."

Derek relaxed and let himself be carried along on a nine-year old girl's tales.

"I spoke to your Mom earlier." Derek whispered as he sat down beside Casey in the library. Casey looked up.

"Oh?"

"She wants to know if you are eating properly or getting too thin."

Casey rolled her eyes. "What did you say?"

"I told her you _felt_ alright to me." He smirked.

She turned to him in horror.

"_Der-ek!"_ She whispered. He smirked.

"Relax. I said you look okay as far as I could tell. _Are_ you eating properly?" He asked. His eyes were curious.

"Fine. Apart from my boyfriend keeps taking me to fast food joints."

"Hey. At least I pay."

"You do, don't you? I should pay my own way."

"When you need to pay, I'll tell you."

"Ok."

"Case?"

"Hmm. You finished studying, yet?"

"No Derek."

"Come on. We could go to the movies with Jez."

"You go to the movies. I'm studying."

"You're being a very neglectful girlfriend, Casey. I might have to trade you in. Plenty of other girls out there."

Casey narrowed her eyes.

"Yes. There are. So faced with a diner full of doe-eyed girls and a need for an urgent girlfriend, why did you pick _me_? Aren't I the least attractive of the lot, after all, I am your _step-sister."_

Derek thought on his feet. "Ah. But where's the fun in that? At least this way I get to distract Jez – and bug the hell out of you."

There was more to it, she knew. But she couldn't be bothered to fish right now.

"Come on, girlfriend. Let's go the movies."

"Okay." She gave in.

They went with Jez, Caroline, Leesa and Petra to see a horror movie. As Jez was sitting next to Casey, Derek threw an arm around her and pulled her towards him.

"Knock it off, you two. I don't want to hear slurping in my ear." Jez grouched. Derek chuckled and Casey blushed in the darkness. But, it was a late showing, and she was comfortable resting against Derek. The film was fairly boring and when Derek heard a noise by his ear and looked at the girl in his arms, Casey was sound asleep.

Derek drove them back to the dorms, Casey couldn't stop yawning. He parked the car by Casey's dorm as she was currently the 'keeper of the car'. Everyone piled out and Jez set off straight away, anticipating Derek hanging back to say goodbye. Casey's friends began to walk away too.

"Your keys, I believe."  
"Thanks." Casey yawned. "See you in the morning as normal?" She leaned forward for the statutory kiss.

"Night Sleepy head." Derek released her. She turned and went inside, and he watched until he saw her room light come on.

Walking back to his own dorm, Derek smiled. It was bizarre, and totally against the Derek code of conduct. But, something about this whole situation with Casey McDonald worked. He smirked. They had done the movies, now, so he spent the rest of the walk home trying to think of other ways he and Casey could be forced to spend time together in the company of their friends, "maintaining their cover."

**Chapter 12: Mr "No PDA"**

"Are you seeing Derek today?" Leesa asked over breakfast. Casey nodded.

"When isn't she seeing Derek?" Caroline chuckled. "Those two are joined at the hip."

Casey laughed. "Not exactly. Derek's just…attentive. He says if he's going to have a girlfriend he wants her to be seen with him."

"So are you going to move in with him next semester?"

Casey shook her head. "My Mom would freak out."

_And that is the understatement of the year._

"Does she like Derek?"

"Yeah." _Because he's her _step-son_. _"Just not enough to sanction me living with him."

"She can't actually stop you."

Casey looked pointedly at Caroline. "Would you like to have that conversation with _your_ mother?"

Her friend giggled. "No. Probably not. What are you doing with Derek today?"

"Studying."

Caroline raised two eyebrows.

"Studying, Caroline and only studying. I've told him if he wants to spend time with me he is going to have to do some of the things I do. And that includes studying." Actually, the conversation had been almost exactly that. Casey was finding her opportunities for studying had been reduced by the whole "girlfriend" fiasco so she was insisting on dedicated studying time. And Derek had decided if you can't beat them…join them; at least it would keep his grades up. So far Derek wasn't doing too badly at college.

And he didn't mind studying so long as it was in public and required the odd instance of cover-maintaining (kissing Casey, to you and me).

"Do you know if Derek's roommate is seeing anyone?" Caroline asked. Casey's eyes widened. She shook her head.

"Jez isn't interested."  
"How do you know? Has he said something?"

"No. But between you and me, Derek let slip that Jez is…not interested in our half of the population."

That was too polite for Caroline, she had no idea what Casey was talking about.

"What?"

"He's gay."

"Oh….Oh." Well that was that then. Strange because Caroline had been convinced on more than one occasion that Jez was checking her out. But Derek would know of course.

They had found a quiet corner in the cafeteria. Students often used the large room for meeting and studying when it wasn't a mealtime. Casey had spread her books out and she looked pointedly at Derek until he did the same.

"You're serious about studying."

"Yes Derek."

He sighed. "Okay."

After a while, Casey looked up at him.

"Can I ask you a question?"

"Sure."

"How come Mr no-PDA suddenly wants to maul his "girlfriend" in the cafeteria?"

Derek smirked. "It's about reputation."

"It always is with you."

He grinned at her. "In the small environment of the school you can rely on word of mouth and graffiti in the restrooms. In the larger environment of college, you need to show people; even if it is with your keener step-sister."

"Am I supposed to find that funny? Because I'm telling you Derek, I don't."

He shuffled closer to her and took her hand.

"I'm showing you affection because I want Jez to back off. And also, I have to say, an added benefit is, Casey, kissing you is actually not the worst thing in the world."

"Was that a compliment?"

"Yeah I guess it was."

Casey leaned forward and kissed him on the mouth.

"Did someone we know just walk in?" He murmured.

"No. Just stoking your rep."

He laughed against her lips and kissed her again.

"D?"

"Hmm."

"As pranks go…this isn't too bad."

"Was that a compliment?"

"Yes. But don't let it go to your head. I'm still dumping your ass a week on Sunday."

He pulled back. "_You're_ dumping _my_ ass?"

"Yup."

"Ah. But Derek Venturi does not get dumped."

Casey laughed and turned back to her studies.

"He does when he dates his "keener" step-sister."

**Chapter 13: Jade**

"Hi Casey!"

Casey looked up from her cereal and found herself looking into the face of Jade, one of the other girls from her course. She was an "other" girl because she and her friends were the height of "cool" and consequently had nothing to do with Casey and her friends. Casey hadn't been aware that Jade even knew her name.

The funny thing was, Casey could have put money on the next few words to spring from the bleached blonde's mouth.

"So. I just wondered if you and your boyfriend wanted to come to my party on Saturday night?"

Typical! It was high school all over again. Well she wasn't going to fall for it.

"Look Jade. If you want Derek to go to your party, just ask him yourself. Don't use me to get to him."

"Hey! I was just trying to be nice."

"No you weren't. You were trying to get me to bring my boyfriend along so that you could steal him out from under my nose. Well I have news for you…you are welcome to him, he's all yours. But, if you want him to go to your party, you are going to have to ask him yourself."

"What's up with you?" The devil asked as he kissed her hello in front of the dorm (and Leesa and co).

"One of the bimbos on my course asked me to a party at her parents' house this weekend." She slung her rucksack on her back with a force that told him the invitation hadn't gone down well.

"And that's a bad thing because….?"

"She doesn't want _me_ to go. She's only inviting _me_ so that she can invite _you_."

"Oh."

"And then when you get there, she'll spend all evening trying to separate us so that she can sneak upstairs with you to some younger sibling's bedroom so that you can do dirty things to each other on top of a Sesame Street bedspread." Casey blew out a breath. "Or at the very least you'll leave with her phone number so that you can call her a week on Monday."

Derek laughed. "Or maybe, I'll spend the entire evening in a corner with my girlfriend."

Casey leant towards him and whispered. "Nice try Derek, but that's _pretend_ girlfriend, and I _know_ you."

_Why am I doing this?_ Casey was arguing with herself as she walked into the party, her fingers laced with Derek's.

"Will you just _relax_?" Derek grinned at her. Her reaction was amusing him because it was so typically Casey. She had made disparaging comments like this about blonde girls before when they were still living at home. It was different this time, because for once it was blatant jealousy, not even hidden under the thin veneer of sisterly concern.

It amused him all the more because it wasn't justified, for two reasons: Firstly, she was only his _pretend_ girlfriend and secondly, Derek was enjoying this pretend-girlfriend farce far too much to be unfaithful…even to…no especially to Casey.

"Hi Casey! And you must be Derek. I've heard a lot about you?"

_Okay. Casey's fear is suddenly a lot more understandable. Jade is quite hot. She reminds me of Amy. Same sort of cruel look about her too. Yes. Casey has interpreted the situation correctly this time. Of course, Jade is at a disadvantage. She isn't Casey. Hell that sounds weird._

_True, but weird._

_So time for a little bet._

"Hey Case." He murmured in her ear. "I bet you that within ten minutes, Jade's best friend is asking you for help in choosing the music."

Casey looked up. "Oh?"

"Separation…"

She rolled her eyes. "Then no bet."

"Trust me Princess, I'm not interested."

Casey looked up at the sincerity in his voice. "You know I might actually believe you."

"You should. I'm having too much fun with this Jez business to screw it up. And I'm not even going to get her phone number for later."

"Oh? Why not?" She looked suspicious.

He shrugged. "Enjoy it Case. For once, it's you I want. Even if it is all pretend."

That made her smile.

"And if you keep smiling like that, I might forget this is all pretend and drag you off to that very nice looking sofa over there and…"

"Hi Casey! I don't suppose you'd come and help me choose some music, would you? I've had complaints about my selection."

Casey looked up at Derek and grinned as he planted a kiss on her lips.

"Behave." She murmured.

"Watch me."

Jade was approaching with two paper cups. Derek was sure it wasn't cherry-ade.

"Here." She said, passing one over. "You might as well have this, it's going spare."

He knew Casey wouldn't particularly approve, but one drink would not hurt. He knew what he was doing.

"So how long have you known Casey?"

"Nearly four years. She went to my school."

"And how long have you been dating her?"

"About six months."

"Wow!"

He grinned. "What's so surprising?"

"I figured you for less…serious relationships."

He shrugged. "I've dated a lot."

"But not since Casey."

He shook his head.

"She must be good."

They both knew what she meant.

"Unbelievable."

"So what's the plan? Date her until something better comes along?"

Ok…Jade outdoes Amy on the cruelty stakes.

"Like you?" He asked.

"Maybe. I mean. It's college. It happens all the time. You date people at high school, things get pretty serious, then you go to college and realise there is more to life. Most high school relationships don't last the first semester."

"And those that do, tend to last a lifetime." His eyes met Jade's. She decided to carry on.

"I mean Casey's nice and pretty enough. But is she enough of a challenge for a guy like you?"

Derek laughed. He laughed a lot. Jade frowned, so he decided to put her out of her misery.

"Jade. Casey McDonald has challenged me every day for nearly four years. When it comes to challenging, she _is_ the champion. _No one_ will ever be more challenging for me than Casey. And she isn't_nice_. She's fantastic and she isn't pretty, she's gorgeous. Maybe the relationship won't last the semester, but I'm telling you now, hun…_If and when_ I'm looking for a replacement, you won't be on my list." He took a sip of his drink. "Nice party." He said, motioning to where people were dancing.

Casey watched the scene from the other side of the room. She couldn't hear what they were saying, but she could see the consternation on Jade's face. She finished helping Jade's friend and then went to sit on the comfortable sofa Derek had mentioned earlier. Two minutes later as he sat down beside her, she smiled and shook her head.

He smirked.

"Okay. What was the hook she tried to reel you in with?"

He slipped his arm behind her.

"She told me she thought you weren't a challenge for me and that she could challenge me more." He spoke against her neck.

Casey laughed.

"If I live to be a hundred and meet a thousand girls a day, I will _never_ find someone who challenges me as much as you."

"Flatterer." Casey said, and let him pull her into a kiss.

**Chapter 14: Lizzie**

"So…" Lizzie's voice echoed from Casey's cell phone. "…how's college?"

"Unbelievable, Liz. You are going to have _so much fun_!"

"I can't wait. It has to be better than high school."

"Oh you have no idea. High school is to college as vinegar is to champagne. The lectures are so interesting, the lecturers so knowledgeable and the facilities so new…the…"

"…and the guys?" Lizzie cut across the rather boring diatribe.

"What guys?"

"The cute, unattached guys that you were going to hook up with as soon as you got to Queens."

"I never said that."

"You did. You said after Truman dumped you that you were fine with it because when you got to Queens it would be full of unattached, cute guys who would sweep you off your feet and read you poetry by the moonlight."

"I may have said something like that, but I'm sure that I never said "hook up"."

Lizzie smiled to herself. "So…come on…the guys. IS there anyone?"

_No Lizzie. Because the person I am swapping saliva with on a regular basis is my (and your) step-brother!_

"I'm still looking."

"So not a pot of gold then?"

Casey smiled and sipped her coffee. She was having this conversation in the cafeteria four days after the party. The party at which, Casey and Derek had spent the entire evening on the sofa, pretending to themselves and each other that their cover was in imminent danger if they didn't "suck face". The memories of it were still causing Casey to float around on a fluffy cloud.

"There are a few possibilities."

The possibility she was thinking of kissed the back of her neck unexpectedly as he sneaked up to her. She threw him a look and motioned to the phone.

"Who is it?" He mouthed.

"Lizzie."

He snatched the phone out of her hand.

"Hey Lizard! How's it hanging? How's my favourite st…OW!" Casey had kicked him.

"Thanks." He mouthed.

"You're welcome."

"Derek?" Lizzie questioned.

"That's me."

"What are you doing with Casey's phone?"

"Well if Klutzilla is foolish enough to make phone calls in the cafeteria where her hunk of a…OW!...where I'm likely to be, she is asking for the said cell phone to get taken. How's Edweirdo?"

Lizzie sighed. "Edwin is….obnoxious!" She finally let out. "He's started pranking me and it is so totally unfair. I mean, it's like he expects me to turn into Casey and fight back or something."

Derek grinned. "And are you? Fighting back I mean."

"You bet I am. Nothing beats a McDonald woman."

_Interesting._ Thought Derek. History repeats itself…He made a mental note to interrogate his brother the next time he was home.

Casey was mouthing something at him.

"I want my phone back."

"Gotta run, hun. Your sister has that look in her eye." He handed the phone back.

Lizzie sighed down the phone. "I really wanted some advice about how to stop Edwin turning into Derek."

Casey chuckled. "I think that battle was lost when he was born. Don't worry. He'll grow up."

"I'm not so sure. The real thing hasn't."

"You'd be surprised, Liz." Casey said, looking across at her pseudo-boyfriend who was smirking at her in a rather attractive way. She hung up as he planted a kiss on her lips.

_Five days to go._ They both thought.

**Chapter 15: The Blow Up Doll**

"I think you should stay the night."

"What?" Casey looked at him in disbelief.

"We're going steady and Jez thinks we've been together for six months, Casey. Even you would probably have put out by now."

"Thanks Derek." She said in a tone that spoke volumes.

"Anyway, he's expecting me to take you back to the room, so I think we shouldn't disappoint him."

"I am not sleeping in the same bed as you."

Derek looked at her in horror. "Of course not. You can sleep in my bed. I'll sleep on Jez's. He won't notice. He never makes it. It's just for appearances, Casey."

"You know by the time we've finished with all this, you are going to need to gift me the car – permanently."

"Not a chance. Now shall we swing by your place for your toothbrush or what?"

There was a small part of Casey which found the idea of spending the night in Derek's room amusing and also rather exciting. She, Casey McDonald was going to spend the night in an all-male dorm. She was so cool!

She was trying not to think about the fact that it meant spending the night with Derek.

She hadn't been in his dorm before, so he was showing her around.

"Kitchen, Bathroom, common room. You want a coffee?" Casey nodded.

"Okay. You stay in the common room. I'll be back in a second. If anyone comes in, try and look hot."

"Hot?"

"Yeah…hot."

"You mean warm?"

"No. Case. I mean, try and look as though you are someone Derek Venturi would actually date. Undo a few buttons or something." Then he was gone.

Casey was fuming. How dare he objectify her! She was a modern, independent woman who did not need to 'undo a few buttons'. She huffed and flopped down into an armchair in disgust.

A rather cute looking guy walked in and flopped on the sofa.

"Might if I?" He motioned to the TV.

"No. Go ahead." She smiled and reached for her top button. _Okay. So maybe two buttons wouldn't hurt._

Derek was taking his time, so, in a slightly better mood, Casey pulled out her cell phone and texted Caroline.

**Staying at Derek's tonight. Don't wait up.**

_Oh I am so evil…and she is SO going to phone me…right about…N_

Ring, Ring.

_So predictable._

"I want details." Caroline didn't even say hello.

"Hi Caroline. How are you?" Casey said pleasantly.

"Pissed at you! Why didn't you tell me this was on the cards? Are you being safe?"

"You sound like my mother."

"Have you got some condoms?"

"Caroline!"

"Well?"

"No."

"Make sure Derek has some. We need to get you an appointment at a clinic tomorrow for birth control."

"Caroline. Who says anything is going to happen?"

"Casey. This is Derek we're talking about. He doesn't ask girls to spend the night so that he can watch them sleep. It's amazing he's waited as long as he has. I assume you two have gone to third base?"

"Caroline. I really don't want to talk about me, Derek and third or Home base!" She blurted. She looked up to see Derek had appeared at her side, coffee cup in hand and a raised eyebrow.

"Whoops. Gotta go." She hung up.

"Let me guess. Best friend thinks she's Nora?"

"Something like that. Thanks." She took the coffee from him. The cute guy on the sofa looked pointedly at Derek.

"Come on. I'll show you my room." Derek said, picking up her rucksack and walking to the door.

The room was quite large, but then it had to be. It had two over-sized single beds, two bedside tables, two wardrobes and two desk-cum-chest of drawers. To her surprise, Derek showed her to the slightly tidier side of the room.

"That's my, or rather, your bed. You can dump your stuff on the chair." He flopped onto the bed the way she had seen him do so many times before. She perched beside him.

"Are you sure this is a good idea?"

He had picked up a magazine.

"Jez thinks I'm a player. So he expects me to sleep with my girlfriend. He expects to be thrown out of our room a couple of times a week so that you and I can…"

"Ew…Are you?" Casey asked, suddenly interested in the way Derek had phrased his statements.

"Am I what?" He was only half listening to her.

"Are you a player?"

Derek looked up at her and experienced the weird sensation of a conscience. She needed to know the truth. He shook his head.

"I have a lot of girlfriends. It doesn't mean I sleep with them all. Doesn't mean I'm a saint either."

"How many?"

"Have I slept with?" She was watching him intently. "One."

"Sally." Casey stated. Derek nodded.

"I might have considered it with Kendra, she was willing enough but she had a tendency to screech 'Der-bear' at inopportune moments. It was off-putting, and there wasn't anyone else I was with long enough."

"Emily would have slept with you."

"I know. She asked me to sleep with her on the first date."

"Why didn't you?"

Derek looked at Casey. "Casey, I may be a lot of things, but I don't treat girls like that. I broke up with Emily because I realised it wasn't actually me she had a crush on, just this idea of what I was like. One of the reasons I was with Sally was because she cut through the crap and ignored the exterior Derek."

"Do you miss Sally?"

"Once in a while. Then she emails me and I realise how far apart we've grown and how we probably weren't that close when we were together. We just needed each other for a period of time."

Casey put her coffee down and rolled onto her stomach.

"I wonder what she'd have made of this mess."

Derek chuckled. "Laughed her freaking socks off. Sally likes you."

"She's a nice person. Far too good for you and too bright to be a Derek girl."

"Are you saying I only date airheads?" He leant towards her.

"Well they do tend to be intellectually challenged."

"And are you including yourself in amongst that list?" He was grinning at her.

"Derek. I am lying on your bed in an all male dorm, about to spend the night with you. I am definitely questioning my own intelligence."

He laughed.

"What are you wearing?" He asked with a degree of disgust in his voice.

"Pyjamas." She sounded surprised.

"Casey. Girlfriends do NOT wear pyjamas on sleep-overs at their boyfriend's dorm. You'll have to walk down the corridor to the bathroom. People will see you and, I'm telling you now, they are not going to see my girlfriend in pyjamas! Here." He opened his wardrobe and removed a cotton, button up, collar-less shirt. "Put that on. Oh and forget about wearing a bra under it, it will show."

"This is just one big peep show for the lads, isn't it?"

"Yup. Welcome to college, hun."

She sighed and started to change. Derek quickly turned his back.

Casey made Derek sit outside the bathroom and wait for her while she cleaned her teeth.

"Sup D-man?" One of his dorm-mates said as he was passing.

"Girlfriend's staying. She's afraid of male bathrooms." He motioned over his shoulder.

"That Casey?"

"Yup."

"She's staying?"

"Yup."

"Well keep the noise down. We are watching classic horror tonight. Don't want too much screaming."

They both smirked.

"Will do. But, what can I say. If I hit the spot…."

His friend chuckled. "Lucky fool. See you around."

Casey in Derek's shirt made his legs go weak. It wasn't hugely thick material and he could tell she had left off the bra as he had asked. Her dancer's figure was fantastic, and the shirt tails fell so that they just covered her panties. As if spending the night in the same room as his step-sister wasn't hard enough!

He followed her down the corridor to their room, slipped the universal "occupied" tie over the exterior door handle and closed his room door behind them.

"We could play cards." She suggested as Derek switched on his sound system. Music was an absolute must. Normally, it was used to cover any sounds from the bedroom. Tonight it was necessary to cover the absence of any sounds.

"Okay. You choose."

They sat on the bed for a while playing Gin.

"Derek."

"Casey."

"Do you think I'm a prude?"

"I think you are choosy. There's actually not a lot wrong with that."

"Could have fooled me!"

"You got pressure from Truman?"

"A bit. It took me a while to relax around him. Sam was sweet and completely innocent. He was quite happy with kissing and eventually second base. Max was more…forward. He tried to hit second base on our second date. He got fed up with me when I wouldn't…help him with third base. We split up a couple of times over that."

"And Truman?" Derek really shouldn't need to know about this…it was…so Casey's own business.

"Truman. Hmmm. The closest I've ever come to going all the way. I am so glad I didn't."

Yeah so was Derek.

"Third base?" He couldn't help asking. Casey bit the inside of her cheek, embarrassed. She nodded.

"What is the big idea with it all, Derek? I just don't understand the fuss."

Derek scooped his cards and hers up and dumped them on the armchair. He flopped back down on the bed and propped himself up on his elbow, looking at her.

"All the fuss about what?"

"Second base, third base. And so on. I mean, kissing. Yeah I get that. It's nice. But, having some guy's hand up your top squeezing your breast like he's making sixth grade lemonade… " She sighed. "And the rest of it all just left me cold."

Derek was having a hard time keeping a straight face.

"Let me guess. It was always…ahem…one way? Did he never…?"

"Return the favour?"

She shook her head.

"Look, I'm not comfortable about talking about this, can we change the subject?"

"Princess. Sex is not dirty. Not if it's done right – or unless you want it to be." He smirked to himself. "If the guy is any good, it's a great experience for both partners."

"And I suppose you're good at it." She snorted.

"I'm better at it than Truman. At least I don't treat my girlfriend like a blow up doll."

Casey sniggered.

"You don't believe me?"

"No."

Casey was interested. She really was. She could not believe she was having this conversation with Derek, but it was that "late night confessional" feeling. Tomorrow she would regret being so honest with him, but tonight, it was like sharing something with a best friend.

Derek rolled onto his back and put a hand on her back.

"If I promise not to go past second base, do you want me to show you what I mean?"

Silence.

More silence.

Casey nodded.

**Chapter 16: Not Past Second Base**

"Not past second base."

"Okay. Unless you ask me to."

Casey smirked. "Are you that sure of yourself?"

"No. I'm that sure you aren't a prude."

She smiled at him. Derek could feel himself starting to shake slightly. This was the first time they were going to kiss in complete privacy with nothing in the way of restraints. In public, it had been hot enough. He wondered at what point she would tell him to stop.

He sat up straight so that their faces were level.

"You want to stop, you tell me okay?"

"Yes."

"Casey?"

"Hmm."

"Friends?"

"Friends." She said and smiled.

"Close your eyes."

Derek didn't start with her lips. He kissed her neck first. He let his lips glide across her skin, pressing little kisses along her collarbone, hairline and behind her ears. At the same time, he was gently massaging her neck and shoulders with his fingers.

"That's nice." She said and leaned back into him slightly. He slid his arms around her waist and kissed her neck. His fingers laced with hers and they played a little game, tracing each other's fingers and palms. He watched their hands, and for a moment, the kissing was forgotten.

"Do you have any idea, how beautiful you are, Casey?" He forgot himself and spoke honestly. She blushed, reminding herself this was part of the game. Derek pressed his lips back against her ear.

"I meant that."

She turned and faced him and he caught her mouth with his own and the kissing began properly.

These kisses were like the few that they had already shared…only better. These were less guarded. These were soft, gentle, but set off a fire burning in parts of Casey she hadn't realised existed.

These kisses were turning her on.

She tried to work out what made the difference, and then gave up. Maybe it was the pressure, maybe the timing or maybe it was just that they had unlocked the restraint between them. Something instinctive was working in her. She raised her hands to his hair and kissed him back with everything she had.

This time when he slipped his tongue into her mouth she didn't resist, she joined her own with his and moved her body closer.

Derek twisted them round and laid Casey back on the bed, and the kissing continued. His hands started to explore, and it felt….right. He undid the buttons on her shirt and let his fingers play along the line from her collar bone down to her navel. His mouth was always on hers, except for the tiny moments when they parted for air. Casey felt his finger tips roaming her collar bone and ribs and then he gently brushed one finger towards her left breast.

"No lemon-ade. I promise." He murmured against her lips. She giggled and kissed him.

A while later, he lifted his head from her lips and smiled at her.

"Don't even think about stopping." She cautioned.

He chuckled. "I proved my point?"

"Not yet."

"Greedy." He chuckled as he kissed his way around her body. Casey groaned.

"Don't let it freak you out."

"It isn't." She pulled his head up to hers for a kiss.

"Tell me to stop."

"No."

So it was down to Derek to be the honourable one.

**Chapter 17: You Just Know**

He supposed this was what they meant when they said you just _know_. He had thought it was possible for a while now. Hell, it had been a possibility since he had met her, but it was now, with her sleeping in his arms that he knew. He would do _anything_ for Casey McDonald.

They had laughed together for a while. Then more kisses, gentler, without an agenda. He wanted to ask where this left them but he was too scared. Casey knew everything would come crashing down around her ears in the morning, but she wanted to live in the now. She wanted to be with Derek. If he had asked her to have sex with him then, she would have screamed "yes!"

But he didn't.

It was five am when she woke. She turned in his arms and it woke him up too.

"I ought to go." She whispered.

"Why?"

"Because this is going to get awkward in a moment and you don't do tears."

"Case."

"Derek, it's okay. Last night was good. Amazing. It was everything it should be and more. But…this thing is make-believe. We have two more days and then we both go back to who we really are. Let's try and get things back on track."

"Casey."

She put a finger to his lips.

"No, love. I'm the grade-grubbing step-sister, remember? Don't argue with me. This is what I want."

He nodded. He couldn't argue with her when she put it like that.

She smiled as she got dressed.

"Don't worry. Two more days and then you can start the pranking again."

_Yeah. But I don't want to. I want to pull you into my arms and hold on to you."_

But doing _anything_ for Casey McDonald meant letting her go.

**Chapter 18: Considering**

Caroline looked across at her sleeping partner. It had been a good job that Casey had decided to stay with Derek tonight. She had been able to have a friend over. It had solved a problem for the friend as well…the alternative had been the couch in the male dorm common room.

Jez stirred.

"Hi gorgeous!" He muttered. "Some night, huh!"

"Yeah…thanks."

Jez looked at her. Not his usual type, but 'beggars can't be choosers' as the saying goes. He really did not understand his recent drought. He normally had the girls falling from the trees for him. Last night had been…okay. Caroline hadn't been as experienced as he had hoped. But she had been nice enough. He let her stroke his arm as she spoke.

"You're pretty good at that…considering."

Jez was busy thinking about some of the other girls on campus and what it might take to get them into Caroline's current position. He took a while to register what she was saying. Then his eyes narrowed and he looked at her suspiciously.

"What do you mean…'considering'?"

**Chapter 19: Roommates**

Derek didn't see Casey until lunchtime the following day – the last full day of their pact. He took her to a restaurant off campus where they could guarantee there would be no other students. He didn't tell her, but he wanted a final, proper date with her. They chose a rounded booth, and while they were waiting for the food, he slid round to sit close to her.

"I feel guilty about last night." Casey said quietly.

"Why? We're both consenting adults."  
She smiled. "I didn't mean that. I meant I behaved like Truman."

Derek frowned. "Sorry. You lost me."

Casey blushed. "You only touched me. I didn't touch you."

He frowned again.

She was right…and he hadn't even noticed. He had been so caught up in Casey, in making her feel pleasure, he hadn't needed her to do the same for him. He certainly wouldn't have rejected her if she had tried, but he hadn't missed it. And yet the night had been one of the best experiences of his life.

"It wasn't about me."

"I still feel guilty."

"Don't." He pressed his lips against hers.

"Derek there's no one we know here. We don't need to keep that up."  
"Shut up and just let me kiss you."

So she did. And the waitress had to cough loudly to get their attention.

That made Casey laugh.

They walked back to the campus holding hands. Derek was fighting himself the whole way. He wanted to stop; to tell her how she was driving him crazy, to ask her to scrap the whole pact thing and just go out with him for real. Coz this whole prank felt nothing like a prank. It felt like he'd fallen hard for Casey.

The trouble was he knew it wasn't what she wanted. And that was the only thing which stopped him.

He did pause on the way back though. Pretended to see someone they both knew and pushed her carefully against a convenient wall. His hands dropped to her waist and her hand rose to his hair as they started to kiss. This, he was not ready to lose. This, unfortunately, he had to give up.

They spent the rest of the afternoon in as public a place as he could find, so that he was forced to spend as much time as possible kissing Casey. She didn't mind. She'd stopped complaining a long time ago. She did wonder why he didn't go off somewhere with his mates, or choose a quieter spot. But as she was in no hurry for tomorrow either, she stayed silent.

"You're quiet." Casey murmured in Derek's ear. She was sitting on his lap in the student bar.

"Sorry. Miles away." He planted a kiss on her neck.

"Are you okay?" She looked concerned.

"Just thinking. 12 hours, 55 minutes and counting."

"In a hurry to be rid of me?"

"No."

Casey raised an eyebrow.

"Desperate to keep you." He admitted finally and tightened his arms around her.

Casey stared at him.

"YOU BASTARD!"

Casey looked up in astonishment. Jez was the other side of the room, bearing down on them.

"How dare you!"

Casey stood up.

"Look Jez." Obviously this was something to do with her.

"YOU…stay out of this. It's your fucking boyfriend I'm pissed at."

"Jez Dude. What's up?" Derek tried blustering. Casey had seen him like this before – It rarely worked.

"You told Caroline, Leesa and Petra that I was gay."

Derek frowned. Actually, he hadn't.

"No. Jez. That was me." Casey intervened. "Derek explained…and when they started to express an interest I just let them down gently."

Her step-brother groaned. _Way to go, Klutzilla!_

"Nice…Except I'm _not_."

"Jez, It's fine…no one is judging you. We're supportive… honestly."

"Casey! Shut the fuck up. I'm NOT gay."

"But Derek…"

"I don't _care_ what Derek told you. I am NOT gay. Of course now, thanks to you and your gossiping friends, the entire female student body thinks I am… no wonder I've been starved all semester!"

Casey turned to Derek. "Derek?"

Could the world please swallow him up? He ran his fingers through his hair.

"Casey. That day in the diner…" He pulled a face. "Jez was talking about trying to pick you up and I didn't like it. So I told him you were my girlfriend. Then when he seemed like he didn't believe me and would still hit on you, I decided to tell you he was gay and that I needed a girlfriend to throw him off. It was the stupidest idea I have ever had. I should have told you right at the start. I've thought about telling you every day since, but these past two weeks – hell Casey! The past two weeks I do not regret. _You're_ going to have to dump _me_, because, sorry Princess, I _can't_ do the dumping." He looked desperately at her.

Silence.

Very long silence.

"Derek Venturi, you are an IDIOT!" She screamed.

More silence.

Long Pause.

Then she laughed and she pushed her way back onto his lap, her fingers sliding into his hair. "**My** freaking idiot, but you're still an idiot."

Derek tightened his grip on her, his fingers brushing bare skin at her waist. "So does that mean you're not dumping me?"

Casey shook her head. "You're stuck with me…sorry." She whispered in his ear.

Derek turned his mouth to her and they eased into a deep kiss.

Jez coughed pointedly.

Casey pulled reluctantly away from Derek, her arms still around his neck and flicked her head towards Jez. "Promise him, you'll fix it."

Derek smirked but his eyes didn't leave Casey's. "Jez dude, leave it with me. I'll have the girls eating out of your hands before the end of the weekend." He lowered his lips to Casey's neck.

"You'd better dude or you can look for a new roommate."

"Oh he's already got one of those." Casey stated as Jez, satisfied, went off in search of Caroline.

Derek looked up at her. "Oh?"

"I want you where I can keep an eye on you."

"Is that a promise?"

Casey grinned. "Definitely. If we room together, I can make sure you're going to classes and studying will be SO much easier when we are under the same roof. We won't have to meet at the cafeteria or library."

Derek pulled a face. Suddenly this was losing its appeal. Living with a keener…this keener…_again._

"…I can show you how to write condensation cards, and efficient revision timetables. And _you_…"

Derek looked up into her eyes and all his blood ran south as he read the level of _desire_ in her eyes. He realised he was being seduced.

"…_you_ can teach me ALL about baseball. Why don't we go make a start now?"

Casey's eyes were full of fire.

And Derek got the joke.

**Chapter 20: Epilogue Summer Break**

**Summer break – several months later.**

"Thanks Casey, I really needed to get out of the house. Edwin is driving me crazy." Lizzie did look frazzled, Casey had to admit. It was one of the reasons she had suggested an extended trip to a mall some distance from London. She saw so little of her younger sister since she had gone away to college.

But spending time with Lizzie was great these days. They had so much more in common. Lizzie was still soccer mad, but she was maturing fast and Casey realised it would not be long before Lizzie was almost as much of an adult as she herself was.

Which was why she had to help Lizzie with her current problem…Edwin.

"Is he pranking you still?"

"Several times a day. And always at the worst times. Like when my boyfriend is picking me up to go to school – he pours hair dye on my best Ts."

"What did you do?"

"I adopted your approach…I borrowed his U2 T and made sure I got tomato sauce down it at lunch time."

Casey smiled.

Lizzie continued. "It's like living with Derek all over again…except now _I'm_ the target." She sipped her hot chocolate again.

"How do you do it Casey? How do you manage to keep living in the same house as Derek…even at college? I mean I know George _made_ you share to save costs, but how do you cope?"

Casey smirked.

"The thing is Liz. Guys don't _do_ emotions. But that doesn't mean they don't _have_ them. You just need to learn how to read them. I've learnt how to read Derek."

"You make it sound like a foreign language."

"It is, hun, it is. The bad news is, I think you are going to have to put up with Edwin for the next couple of years. But, I do have some constructive advice though."

Lizzie reached into her bag and took out a note book.

"Right I'm ready…" She said pen poised.

"Firstly, you need to prep your bedroom. I'll give you a list but you'll need a safe, two identical diaries and the name of a good, unbribable locksmith. Secondly, you need to pay attention to Edwin. It's easy to ignore him, but study your subject. It will give you clues as to when he is likely to prank you, and the severity of the prank. Pay attention to his grades and nag him when they drop – I'll explain that one later. Thirdly, _like_ his girlfriends – nothing gets rid of them quicker than acceptance by his step-sister. Fourthly, date losers. Nothing winds him up faster than seeing you kiss someone he despises – except if you date his best friend.

Fifthly, don't let him stop pranking you.

Six – pay attention to what colleges he is applying to and investigate whether they do your own courses there.

Seven – develop a catchphrase. "Ed-Weirdo!" might work. Make sure you break the first bit into two syllables.

Eight – Look good all the time, even if you are just going to the bathroom.

Nine – try to have the odd, feel-good moment."

Lizzie paused in writing. "And ten?"

"oh yes…ten. If he offers to teach you baseball – say yes…but only if you have left home."

"None of this makes any sense, Casey."

"It will do. I can see me and Derek in you and Edwin. I've been there."

"Cool…I think. But you didn't answer my question. How do you stand being under the same roof as Derek?"

"I live with him Liz."

"Yeah I know…how?"

"No Liz… I _live_ with him. We share a bed. He's my fiancé."

Lizzie jaw dropped.

Casey grinned and waited for the second penny to drop.

"But that would mean that you think Edwin and I will…._oh!_"

Her sister laughed and picked up her drink.

"When the whole Lizwin idea has stopped freaking you out, come find me and I'll tell you how the Dasey happened."

THE END.


End file.
